Skip to main content

Full text of "The manufacture and properties of iron and steel"

See other formats

1000 pounds;.on the other hand, there were 281 cases where the 2-inch test showed greater strength, and the differences are more marked, the largest group showing an increase of from 1000 to 2000. pounds. ,It w$l be .shown by Table XVI-L that the width of the piece has little 'effect upon'the strength, so that these records give, evidence of the reinforcement of the 2-inch test,from the shoulders at the ends. ,                         '               .             ^
SEC. XIVII-The pfBliminar^:test-piece.rGTaiitiD.g that "the test is to !be made on a parallel-sided piece, it has been proposed that the steel be tested by making a trial bar, either round or flat, .rolled from-a small ingot. "It is the custom at Steeltoh to make
r .     . . .                      s. TABLE XVI-H.      ,
Comparison of Angles, with'the Preliminary Test.     
		 DO       .	.-* II   '	' 00     ;	],;
History of test-piece.	1 -	"JO       . ri/pt	P<	rt^.-	
	o a> |---	III.	pP*H	d i* Is	Beducti per ce
Cut from ^-inch and f-inch angles    . . . Rolled from 6-inch, test ingot .      '.....	89 89	41800 42270	60190 60200	28.89 26.44	68.0 42.4
Cut from /o-ihch and jHnh angles   . . . . Rolled from 6-lnch test ingot .        .....	.46 46	'40170 48070	60660 61860	29.05 26.01	66.4 40.0'
Cut from A-inch and f-inch angles   .... Railed from 0-inch test ingot ........	87 87	89710 42900	61520 62980	28.96' 28.10	68.6 88.2
such a preliminary: test, but this is idone merely to classify: the metal. If the bar is rolled under proper 'conditions, its ultimate, strength represents the ultimate; strength of the finished material, land; without regard to any results on elongaiion or other qualifies, the steel is used or laid aside, but these'records have nothing to ;db"with the acceptance! 05 rejection of the material. ''In other iwbr^s, this,test :is bur .own; work,' .while the inspector is to test ^the material that he; buys, as fully as he may wish, without regaxd -''to whether a small test ingot'has or has not fulfilled certain re-rqiirements'.; | . ; - | ' . :                          '?? ; 
Table XVI-H compares! tike data obtained from a large number .of charges of ;acid"6pen-h|eafth steel having a tensile, strength be-tween 56,000 and 64,000 ipqunds per square inch. ''-They were jll